[MIPS] Bigsur supports highmem.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 3778c3b..2c7d6c2 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -546,6 +546,7 @@
 	select SWAP_IO_SPACE
 	select SYS_HAS_CPU_SB1
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_HIGHMEM
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 
 config SNI_RM